The present disclosure herein relates to a semiconductor device, and more particularly, to a cascode switch circuit of a semiconductor device.
An excessive current or voltage due to high operating speed of a semiconductor device or inductance or capacitance in a peripheral circuit may be generated from a semiconductor device. Accordingly, the ability to respond to the surge voltage of a semiconductor device is required. The surge voltage refers to an excessive waveform of electrical current, voltage, or power. Such the surge voltage may radiate a thermal energy enough for destroying an electronic component. This results in a reduced service life or function deterioration of a semiconductor device. The repetition of small surge voltage may deteriorate and destroy semiconductor circuits configuring a semiconductor device. Alternatively, strong surge voltage may destroy a semiconductor device at a time.
As one of a semiconductor device, there is a switch circuit. A switch circuit used for a power electronic system requires high breakdown voltage, normally-off operating characteristics, low-on resistance, high-current characteristics, and high-speed switching characteristics. Especially, when a switching circuit available for a high-speed switching operation is used, the sizes of an inductor and a capacitor in a power electronic system may be reduced. Therefore, the size and manufacturing cost of a power electronic system may be reduced. Additionally, a cascode switch circuit may be manufactured using a device having normally-on operating characteristics. Such a cascode switch circuit may have high current characteristics with low manufacturing cost and size.
Accordingly, a cascode switch circuit that combines a device having low breakdown voltage and normally-off operating characteristics and a device having high breakdown voltage and normally-on operating characteristics is studied. However, such a cascode switch circuit also may be vulnerable to surge voltage or current. Therefore, in designing a cascode switch circuit, a method of increasing a resistance to such a surge voltage is studied.